The present invention generally relates to apparatus and methods for directing and feeding wire and in most preferred aspects to wire directing and feeding apparatus and methods for welders.
Directing wire to its destination or point where it is put to use requires the use of devices including, but not limited to, rolls, orifices, spools, drums, blossoms or other freeforms. One process where it is necessary to direct wire is where wire is used for joining materials by wire welding. This process involves the controlled process of delivering electrified wire to a workpiece. An electric circuit is completed at the junction where the electrified wire contacts the workpiece. This point of contact has the highest electrical resistance of any point in the circuit and therefore results in the point of highest heat. The controlled delivery of electrified wire must be at a rate sufficient to fuse the workpiece and wire to yield the desired properties.
Historically, the mechanics to propel and guide wire to the workpiece utilized a minimum of one driven roll and one pressure roll to insure mechanical contact of the wire to the driven roll. The wire is pulled into the driven and pressure rolls through an orifice type wire guide and pushed out of the driven and pressure rolls through a second orifice type guide and into a wire guide tube towards a mechanism that directs the wire to the workpiece. This latter device is commonly referred to as a gun. This gun is manually or automatically positioned to direct the wire to the junction being welded.
Prior wire guides at the entrance and exit of the drive rolls are subject to a great quantity of abrasion, resulting in short life of the orifice diameter and increased mechanical resistance in the system. When the mechanical resistance becomes excessive, soft wire will pile up in backlash fashion that results in work delays and shortened tempers. There is a consequent need for frequent changes of prior orifice wire guides. The replacement of these wire guides requires that the wire be removed and then rethreaded through the system after the guides have been replaced. Adept fingers and small tools are required to replace the many small parts of prior wire guides. In a cramped space with big cold fingers and very low light, the process can be very challenging. Frequently, parts are lost inside the system and can cause serious damage and delays in work. Under these conditions, threading the wire into an orifice again can alter the attitude of the finest craftsman.
Thus, a need exists for novel methods and apparatus for directing and feeding wire which circumvents all the deficiencies and overcomes the problems of prior wire feeding apparatus and methods.
This need and other problems in the field of wire directing and feeding and especially in the field of wire feeding in welders has been satisfied by providing, in the preferred form, first and second guide plates which are removably held with their first surfaces of linear portions abutting together and including a trough extending through the linear portions and of a size for slideable receipt of the wire and which are positionable in the apparatus by movement of at least one of the guide plates in a direction parallel to the movement direction of the wire.
In preferred aspects of the present invention, the wire is drawn by being captured between counterrotating driven roll and pressure roll extending through openings in the first and second guide plates, respectively. In most preferred aspects, the guide plates are slid parallel to the wire feed direction through a slit of a mount and into a slot of an adapter element, with the guide plates being held in position by receipt of the rolls in the openings of the guide plates. Additionally, in most preferred aspects, the driven roll is stationary relative to the slit and the slot and the slot includes an entry portion allowing insertion of the first guide plate by canting past the driven roll.
It is thus an object of the present invention to provide novel apparatus and methods for directing wire.
It is further an object of the present invention to provide such novel wire directing apparatus and methods having particular utility in connection with welders.
It is further an object of the present invention to provide such novel wire directing apparatus and methods which feed the wire.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides which can be removed and replaced without the use of tools.
It is further an object of the present invention to provide such novel wire directing apparatus and methods which does not include small, easily lost components.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides having extended life and minimizing, if not eliminating, the need for replacement.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides which minimize mechanical resistance to wire movement.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides which can be replaced without requiring removal and rethreading of the wire.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides having a tubular track rather than being of an orifice type.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including easily fabricated and assembled components of a minimal number.
It is further an object of the present invention to provide such novel wire directing apparatus and methods including guides which can be easily replaced in low light, cramped spaces.
These and further objects and advantages of the present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings.